Abstract
A light up-conversion effect has been observed in the ZnSe–ZnTe superlattices with a modulated periodicity. A photoluminescence (PL) peak at 2.1 eV is observed in the samples even under excitation by an He–Ne laser (633 nm, 1.96 eV). The samples, which we grow on InP by molecular beam epitaxy, consist of a combination of two kinds of superlattices. The PL spectrum, measured by using an He–Cd (325 nm, 3.81 eV) or Ar + (488 nm, 2.54 eV) laser as the excitation source, indicates two peaks due to the respective superlattices at 1.9 and 2.1 eV. The intensity of the up-converted peak has a super-linear dependence on the excitation intensity. The mechanism of the effect has been explained by a dual-subband model.
Published Version
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